创建新的lucene索引没有找到类错误

Question

i'm using lucene 4.0 and i want to create a new indexWriter in this way:

IndexWriter index = LuceneUtils.createIndexWriter(indexPath, true);

(it worked using lucene 3.6) where indexPath is a String with the path of the index. I got this error:

Exception in thread "main" java.lang.NoClassDefFoundError: org/apache/lucene/analysis/SimpleAnalyzer
at lucene.IndexCreator.<init>(IndexCreator.java:25)
at main.Main.main(Main.java:72)
Caused by: java.lang.ClassNotFoundException: org.apache.lucene.analysis.SimpleAnalyzer
at java.net.URLClassLoader$1.run(URLClassLoader.java:202)
at java.security.AccessController.doPrivileged(Native Method)
at java.net.URLClassLoader.findClass(URLClassLoader.java:190)
at java.lang.ClassLoader.loadClass(ClassLoader.java:306)
at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:301)
at java.lang.ClassLoader.loadClass(ClassLoader.java:247)
... 2 more

i have read that i need to add lucene-analyzers-common-4.0.0.jar to the project besides lucene-core-4.0.0.jar , but i get the same error. as a matter of fact the path of SimpleAnalyzer.class inside lucene-analyzers-common-4.0.0.jar is not org.apache.lucene.analysis.SimpleAnalyzer but org.apache.lucene.analysis.core.SimpleAnalyzer .

Answer 1

It looks like you might have a 3.6 jar in your class path. Can you verify that an older version isn't being pulled in, possibly by transitive dependencies?

Answer 2

You have an older version of lucene-core jar in your project. The path for class SimpleAnalyzer in previous versions was org.apache.lucene.analysis.SimpleAnalyzer . During compile time the system is able finds SimpleAnalyzer on that path. But during runtime it refers to the new version. Now the class exists in lucene-analyzers-common-4.0.0.jar under a different path. Hence NoClassDefFoundError.

You can understand it further by reading this - http://javareferencegv.blogspot.com/2013/10/debugging-javalangnoclassdeffounderror.html